Swivel-head drill holder



April 5, 1927. J. NELSON swxvm; HEAD DRILL HOLDER Filed June 23'. 1921 '2 Sheets-Sheet 1 1 2 7 J. v. NELSON swivE'L HEAD DRILL HOLDER Filed June 23, 1921 Z'Sheets-Sheet 2 v fafzrz 7 3757 ciao/2 wskics Patented Apr. 5, 1927.

U-NI-TE'D- STATES 1,623,747 PATENT OFFICE.

, JOHN VICTOR NELSON, F MAYWOOD, ILLINOIS AS SIGNOR T0 FRANZ K. KB/AG, 0F

a i a v I p CHICAGO, ILLINOIS.

SWIVEL-HEAD niunnnqztnnn.

Application filed'J'une 2? 1921. Serial No. 479,838.

This invention relates to "drilling attachments for milling machinesfof the general character shown in my. Patent No. 1,397,696,

granted November 22, 1921. l

The main objects of .theinvention are to providean improved form of swivel-head and mechanism therefor; to provide a better form of power transmission 'i'neans including a belt; to provide a simple anddependable automatic belt tightenertheretor to provide yielding friction meansfor holding the drill spindle against slipping lengthwise by gravity; to provide an improved form of interchangeable drill guide bushing and means for seouring same; and to provide an improved formofantifriction thrust bearing for the drill holder. An illustrative embodiment of this inven- N tion is shown inthe accompanying drawings in which+ 1 is a front elevation Jofthe swivelhead tilted clockwise to a horizontal position. Fig. 2 ismainly a planotthe device positioned as in Fig. 1, part being broken away to show the speed gearing,'and shows'also the adjacent end of the stationary hub of the drill"attachmentbracket." p ,1

Fig. 3 is'a lan or the swivel-head in its normal upright position and shows also part of the fixed hub. f.

Fig. at is anenlarged; sectional detail of the clt tightener, on the line 14'ofFig. 2. Fig. 5 is a sectiononthe'line 5-5 of Fig. 2.- l

Fig. 6 is air-axial section of the antifriction drill bearing thrust sleeve: onthe line 6'6 of Fig. 2, the drill spindle being in side elevation, i 1 v p In the construction shown in the drawings the swivel-head 1 is rotatably attached coaxially to the hub of'the fixed bracket 2, which in turn is demountably secured to a millingmachine (not shown), as explained in my said patent" The parts 1 and 2 are clampedtogether releasably by bolts 3 arranged parallel with the swivel axis of the device and adapted to facilitateready adjustment of the tilt ofthe swivel-head. Said tilt or inclination maybe measured by the gage marks lvat the base of the head. 1 Mounted on the head 1 a-longitudinally movable non-rotary sleeve 4 in which is swiveledv a drillspindle 5 disposed crosswise of the head 1. Said spindle is driven by a This is more fully explained in said patent.

secondary pulley 6, belt 7, a primary pulley 8,

The swivel-head 1 is in the form of a hollow frame, the base of which contains the gearing 9 to increase the speed of said primary pulley 8 The head 12 ofshatt 10 is provided with a diainetral slot 13 to receive the corresponding end rib or shoulder 14 ofthe tapered shaft 11. The pulley 6 is splined on spindle'5.

The opposite end of shaft 10 from said head 12 is provided with a rigidly attached gear 15 which meshes with a relatively small gear 9 fixed on the shaft-17. Said shaft 17 has also a larger gear 18 meshing with a relatively smallgear 19 fixed coaxially upon the hub of pulley 8, whereby a rather high speed is imparted to said pulley. The drill I speed is still further increased by reason of pulley 8 being much larger than the secondary pulley 6. The pulley 8 fits rotatably against the head 12 10 as a bearing. The'drill spindle 5 being disposed at a right angle to shaft 10, the" belt 7 is ai and turns on shaft 1 ranged to operate on direction changers or idle pulleys 20, 21 and 22 which are mounted on the frame in a position to receive the belt 7 in alinement with the corresponding grooves of pulleys and 8. One of these idlepulleys, namely 21, serves to maintain substantially constant belt tension and for this purpose is mounted on a sliding sup port or carriage 23 movable toward or away from pulley 8 and shaft 10. The belt tends to draw said carriage inwardly against the expansive force of a helical compression spring 24. Said pulleys 21 and 22 receive the relatively slack side of the belt. Hence, in case ofvariable load the. peripheral speed of both pulleys remain the same and the operation of the belt tightener the relative speeds ot'pulleyst In order to compensate for position of said pulley 21, the third idler and 8.

22, of relatively small size, is mounted between pulleys 6 and 21 andis so positioned as to assure alinement of the slack side of the belt with the groove otpulley 6.

the variable does not vary ill The frame 1 includes a base part having an aperture 215 on each, side to give access to the connection 11-12. The middle part of said frame is provided with a journal bearing member 27 secured to the barrellike interior of said frame for mounting the gear shaft 17 and associated members, said journal bearing member being secured by screws 28. An arm 2,) projects from said frame 1 opposite member 27 in a direction papallel with the spindle 5 to. support the idle pulleys 20 and 2],, and the carriage 2?} for the latter. The forward part of said frame 1 includes a pair of oppositely disposed arms. 30 andjll substantially parallel withspindlei) to support the drill guide 32 and journal bearings 3.3 and 31- for spindle 5. t'jitilh another arnr 55 provided on said frame to hold. the sleeve l in alinement with. said. drill. guide :32 and bearings 33 and 34:,

The idle pulley carriage 23 is in the form Of av cylindrical rod having a lateral. projection or arm to which is secured the pivot 37 for pulley 21. Said rod 23 fits. in a oylindrical pocket 38 in the base of which is housed a spring 24;, and the arm. 36 slides in a longitudinal groove. 39, whereby axial turning of said carriage is prevents The support for sleeve 4 is. a barrel.- shaped or nearly cylindrical with a bore adapted to receive the sleeve 4 in. snug. lit.- ting relation. The inner of sleeve dis provided with a rack 4:0, tl1e teeth of which coact with the hand-controlled thrust gear 41 having a handle 42. Said sleeveandgear are so formed, as shown by Fig. 5,, that axial turning of said sleeve is prevented,

In order to provide for manual setting of sleeve 4: or adjustment of the. operation thereof, a handle 43 is provided having. a threaded shank let screwed into the men ber 35, which shank is, hollow and provided with a yielding member l5 urged by spring :16 against and into frictional engagement with sleeve -l. Said spring is helical in shape and arranged to operate by compresT sion. the tension being inc *ased or diminished by turning the handle correspondiugly clockwise or the reverse.

The outertip of arm 30 is provided with a split ring at? having a cylindrical bore l8 to receive the interchangeable drill guide 32. In order that. said guide may be readily secured or released. a clamping screw 49 is provided to pull, the ends. together where the ring is split. as will be understood. In order topositively. lock the cylindrical guide in place, a. spring actuated pin 50 is mounted in a perforation disposed crosswise of the guide 32 on the inner side of the latter and in a position to tangentially engage a peripheral groove 52 on. said guide. Said pin 50 is of somewhat larger diameter at one end than at the other so that when partly retracted the relatively small end does not engage said groove 52 but leaves the guide 32 free for extraction. Y When, however, the pin 50 is released it is forced forward by its actuating spring so that the thick part enters groove 52 and so locks the guide 32 in place. The tip of pin 50 normally projects son'iewhat so as to be accessible. for. forcing inward readily by manual means to release the guide member 32.

In order to eliminate friction to the highestdegnee possible, the thrust sleeve :lis provided with annular anti-friction bearing means :uljacent to the drill head 53, said bearings including a plurality of balls 5i enacting between the non-rotary sleeve -l and rotary slu uldcr member 55 on the 'lorwa d end of spindle 5,

The operation of the above described at.- tachnient is as follows: The fixed bracket 2 having beeir attached to an appropriate machine as will be understood, and properly connected to receivepower, a drill isv placed in the. head 53 and a corresponding guide member. 32. is placed in the arm 30. The swivel-head l is then adjusted by loosening screws 3, tilting to the required degree as measured by gage marks 1, and again setting thescrews 3. The power being turned on, the drill is appliedto the work by turning. the handle 42 counter-clockwise, thereby advancing the sleeve 4, The larger the drill or the more pressure is applied through handle. 42, the more a tendency will develop for the belt to slip, which however is compensated for by the outward movement of the idler pulley 21 on its carriage 23 so that premature belt slippage is avoided. In case the size of drill is to be changed, the screw 49 is. released and pressure is applied to the pin 50 sufiioiently to release the cap 3 2, which may then be Withdrawn and the desired size of guide inserted in its place, whereupon the pin 50 is released and the screw d9 set to clamp the guide tightly in place.

Although but one specilie embodiment of this invention has been herein shown and described. it will be understood that numerous. details of the construction shown may be altered or omitted without departing from the spirit of this invention as defined by the following claims.

I claim:

1. A drilling attachment comprising a head, adapted to. be tiltably mounted on a part of a machine frame having a drive shaft, a driven shaft journalled in said head in alignment with the drive shaft and operatively connected the reto, a pulley on said driven shaftiournalled in. said head which head includes a plurality of spaced arms with aligned bearing openings therein, arranged in a plane at a right angle to said drive and driven shafts, a feed sleeve mounted in oneof said arms, a drill spindle journalled in said sleeve and in one of said other arms, a pulley on said drill spindle for driving the same, a belt operatively connecting said pulleys together,two idle pulleys journalled on said head and aboutvv which said'belt is trained for changing the direction thereof, a movable spring pressed block slidably mounted in said head and upon which one of said idle pulleys is mounted for imposing a tension on said belt, and a third pulley journalled in the head for engaging the belt between said pulley 0n the spindle shaft and said pulley on the block for holding straight that portion of the belt leading to the spindle pulley irrespective of the location ofthe pulley on said,

spring pressed block.

2. A drllling attachment comprising a head adapted to be tiltably mounted on a part of a machine frame having a drive shaft, a driven shaft journalled in said head in alignment with the drive shaft and operatively connected thereto, a pulley loosely mounted on said driven shaft, speed increasing gearing between said driven shaft and pulley, a plurality of arm extensions on said head, having aligned bearing openings therein, arranged in a plane at right angles to said drive and driven shafts, a feed sleeve mounted in one of. said arms,

a drill spindle journalled in said sleeve and in one of said other arms, a pulley on said drill spindle for driving the same, a belt operatively connecting said pulleys together, two idle pulleys journalled on said head ing the direction thereof, and a movable spring pressed block slidably mounted in said head and upon which one of said idle pulleys is mountedfor imposing a tension 011 said belt, and a third idle pulley jour- J OHNYVICTOR NELSON.

about which said beltis trained for chang- 

